xref: /openbmc/linux/kernel/trace/trace.h (revision d623f60d)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 
3 #ifndef _LINUX_KERNEL_TRACE_H
4 #define _LINUX_KERNEL_TRACE_H
5 
6 #include <linux/fs.h>
7 #include <linux/atomic.h>
8 #include <linux/sched.h>
9 #include <linux/clocksource.h>
10 #include <linux/ring_buffer.h>
11 #include <linux/mmiotrace.h>
12 #include <linux/tracepoint.h>
13 #include <linux/ftrace.h>
14 #include <linux/hw_breakpoint.h>
15 #include <linux/trace_seq.h>
16 #include <linux/trace_events.h>
17 #include <linux/compiler.h>
18 #include <linux/trace_seq.h>
19 #include <linux/glob.h>
20 
21 #ifdef CONFIG_FTRACE_SYSCALLS
22 #include <asm/unistd.h>		/* For NR_SYSCALLS	     */
23 #include <asm/syscall.h>	/* some archs define it here */
24 #endif
25 
26 enum trace_type {
27 	__TRACE_FIRST_TYPE = 0,
28 
29 	TRACE_FN,
30 	TRACE_CTX,
31 	TRACE_WAKE,
32 	TRACE_STACK,
33 	TRACE_PRINT,
34 	TRACE_BPRINT,
35 	TRACE_MMIO_RW,
36 	TRACE_MMIO_MAP,
37 	TRACE_BRANCH,
38 	TRACE_GRAPH_RET,
39 	TRACE_GRAPH_ENT,
40 	TRACE_USER_STACK,
41 	TRACE_BLK,
42 	TRACE_BPUTS,
43 	TRACE_HWLAT,
44 	TRACE_RAW_DATA,
45 
46 	__TRACE_LAST_TYPE,
47 };
48 
49 
50 #undef __field
51 #define __field(type, item)		type	item;
52 
53 #undef __field_struct
54 #define __field_struct(type, item)	__field(type, item)
55 
56 #undef __field_desc
57 #define __field_desc(type, container, item)
58 
59 #undef __array
60 #define __array(type, item, size)	type	item[size];
61 
62 #undef __array_desc
63 #define __array_desc(type, container, item, size)
64 
65 #undef __dynamic_array
66 #define __dynamic_array(type, item)	type	item[];
67 
68 #undef F_STRUCT
69 #define F_STRUCT(args...)		args
70 
71 #undef FTRACE_ENTRY
72 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print, filter)	\
73 	struct struct_name {						\
74 		struct trace_entry	ent;				\
75 		tstruct							\
76 	}
77 
78 #undef FTRACE_ENTRY_DUP
79 #define FTRACE_ENTRY_DUP(name, name_struct, id, tstruct, printk, filter)
80 
81 #undef FTRACE_ENTRY_REG
82 #define FTRACE_ENTRY_REG(name, struct_name, id, tstruct, print,	\
83 			 filter, regfn) \
84 	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print), \
85 		     filter)
86 
87 #undef FTRACE_ENTRY_PACKED
88 #define FTRACE_ENTRY_PACKED(name, struct_name, id, tstruct, print,	\
89 			    filter)					\
90 	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print), \
91 		     filter) __packed
92 
93 #include "trace_entries.h"
94 
95 /*
96  * syscalls are special, and need special handling, this is why
97  * they are not included in trace_entries.h
98  */
99 struct syscall_trace_enter {
100 	struct trace_entry	ent;
101 	int			nr;
102 	unsigned long		args[];
103 };
104 
105 struct syscall_trace_exit {
106 	struct trace_entry	ent;
107 	int			nr;
108 	long			ret;
109 };
110 
111 struct kprobe_trace_entry_head {
112 	struct trace_entry	ent;
113 	unsigned long		ip;
114 };
115 
116 struct kretprobe_trace_entry_head {
117 	struct trace_entry	ent;
118 	unsigned long		func;
119 	unsigned long		ret_ip;
120 };
121 
122 /*
123  * trace_flag_type is an enumeration that holds different
124  * states when a trace occurs. These are:
125  *  IRQS_OFF		- interrupts were disabled
126  *  IRQS_NOSUPPORT	- arch does not support irqs_disabled_flags
127  *  NEED_RESCHED	- reschedule is requested
128  *  HARDIRQ		- inside an interrupt handler
129  *  SOFTIRQ		- inside a softirq handler
130  */
131 enum trace_flag_type {
132 	TRACE_FLAG_IRQS_OFF		= 0x01,
133 	TRACE_FLAG_IRQS_NOSUPPORT	= 0x02,
134 	TRACE_FLAG_NEED_RESCHED		= 0x04,
135 	TRACE_FLAG_HARDIRQ		= 0x08,
136 	TRACE_FLAG_SOFTIRQ		= 0x10,
137 	TRACE_FLAG_PREEMPT_RESCHED	= 0x20,
138 	TRACE_FLAG_NMI			= 0x40,
139 };
140 
141 #define TRACE_BUF_SIZE		1024
142 
143 struct trace_array;
144 
145 /*
146  * The CPU trace array - it consists of thousands of trace entries
147  * plus some other descriptor data: (for example which task started
148  * the trace, etc.)
149  */
150 struct trace_array_cpu {
151 	atomic_t		disabled;
152 	void			*buffer_page;	/* ring buffer spare */
153 
154 	unsigned long		entries;
155 	unsigned long		saved_latency;
156 	unsigned long		critical_start;
157 	unsigned long		critical_end;
158 	unsigned long		critical_sequence;
159 	unsigned long		nice;
160 	unsigned long		policy;
161 	unsigned long		rt_priority;
162 	unsigned long		skipped_entries;
163 	u64			preempt_timestamp;
164 	pid_t			pid;
165 	kuid_t			uid;
166 	char			comm[TASK_COMM_LEN];
167 
168 	bool			ignore_pid;
169 #ifdef CONFIG_FUNCTION_TRACER
170 	bool			ftrace_ignore_pid;
171 #endif
172 };
173 
174 struct tracer;
175 struct trace_option_dentry;
176 
177 struct trace_buffer {
178 	struct trace_array		*tr;
179 	struct ring_buffer		*buffer;
180 	struct trace_array_cpu __percpu	*data;
181 	u64				time_start;
182 	int				cpu;
183 };
184 
185 #define TRACE_FLAGS_MAX_SIZE		32
186 
187 struct trace_options {
188 	struct tracer			*tracer;
189 	struct trace_option_dentry	*topts;
190 };
191 
192 struct trace_pid_list {
193 	int				pid_max;
194 	unsigned long			*pids;
195 };
196 
197 /*
198  * The trace array - an array of per-CPU trace arrays. This is the
199  * highest level data structure that individual tracers deal with.
200  * They have on/off state as well:
201  */
202 struct trace_array {
203 	struct list_head	list;
204 	char			*name;
205 	struct trace_buffer	trace_buffer;
206 #ifdef CONFIG_TRACER_MAX_TRACE
207 	/*
208 	 * The max_buffer is used to snapshot the trace when a maximum
209 	 * latency is reached, or when the user initiates a snapshot.
210 	 * Some tracers will use this to store a maximum trace while
211 	 * it continues examining live traces.
212 	 *
213 	 * The buffers for the max_buffer are set up the same as the trace_buffer
214 	 * When a snapshot is taken, the buffer of the max_buffer is swapped
215 	 * with the buffer of the trace_buffer and the buffers are reset for
216 	 * the trace_buffer so the tracing can continue.
217 	 */
218 	struct trace_buffer	max_buffer;
219 	bool			allocated_snapshot;
220 #endif
221 #if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)
222 	unsigned long		max_latency;
223 #endif
224 	struct trace_pid_list	__rcu *filtered_pids;
225 	/*
226 	 * max_lock is used to protect the swapping of buffers
227 	 * when taking a max snapshot. The buffers themselves are
228 	 * protected by per_cpu spinlocks. But the action of the swap
229 	 * needs its own lock.
230 	 *
231 	 * This is defined as a arch_spinlock_t in order to help
232 	 * with performance when lockdep debugging is enabled.
233 	 *
234 	 * It is also used in other places outside the update_max_tr
235 	 * so it needs to be defined outside of the
236 	 * CONFIG_TRACER_MAX_TRACE.
237 	 */
238 	arch_spinlock_t		max_lock;
239 	int			buffer_disabled;
240 #ifdef CONFIG_FTRACE_SYSCALLS
241 	int			sys_refcount_enter;
242 	int			sys_refcount_exit;
243 	struct trace_event_file __rcu *enter_syscall_files[NR_syscalls];
244 	struct trace_event_file __rcu *exit_syscall_files[NR_syscalls];
245 #endif
246 	int			stop_count;
247 	int			clock_id;
248 	int			nr_topts;
249 	bool			clear_trace;
250 	struct tracer		*current_trace;
251 	unsigned int		trace_flags;
252 	unsigned char		trace_flags_index[TRACE_FLAGS_MAX_SIZE];
253 	unsigned int		flags;
254 	raw_spinlock_t		start_lock;
255 	struct dentry		*dir;
256 	struct dentry		*options;
257 	struct dentry		*percpu_dir;
258 	struct dentry		*event_dir;
259 	struct trace_options	*topts;
260 	struct list_head	systems;
261 	struct list_head	events;
262 	struct trace_event_file *trace_marker_file;
263 	cpumask_var_t		tracing_cpumask; /* only trace on set CPUs */
264 	int			ref;
265 #ifdef CONFIG_FUNCTION_TRACER
266 	struct ftrace_ops	*ops;
267 	struct trace_pid_list	__rcu *function_pids;
268 #ifdef CONFIG_DYNAMIC_FTRACE
269 	/* All of these are protected by the ftrace_lock */
270 	struct list_head	func_probes;
271 	struct list_head	mod_trace;
272 	struct list_head	mod_notrace;
273 #endif
274 	/* function tracing enabled */
275 	int			function_enabled;
276 #endif
277 	int			time_stamp_abs_ref;
278 	struct list_head	hist_vars;
279 };
280 
281 enum {
282 	TRACE_ARRAY_FL_GLOBAL	= (1 << 0)
283 };
284 
285 extern struct list_head ftrace_trace_arrays;
286 
287 extern struct mutex trace_types_lock;
288 
289 extern int trace_array_get(struct trace_array *tr);
290 extern void trace_array_put(struct trace_array *tr);
291 
292 extern int tracing_set_time_stamp_abs(struct trace_array *tr, bool abs);
293 extern int tracing_set_clock(struct trace_array *tr, const char *clockstr);
294 
295 extern bool trace_clock_in_ns(struct trace_array *tr);
296 
297 /*
298  * The global tracer (top) should be the first trace array added,
299  * but we check the flag anyway.
300  */
301 static inline struct trace_array *top_trace_array(void)
302 {
303 	struct trace_array *tr;
304 
305 	if (list_empty(&ftrace_trace_arrays))
306 		return NULL;
307 
308 	tr = list_entry(ftrace_trace_arrays.prev,
309 			typeof(*tr), list);
310 	WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
311 	return tr;
312 }
313 
314 #define FTRACE_CMP_TYPE(var, type) \
315 	__builtin_types_compatible_p(typeof(var), type *)
316 
317 #undef IF_ASSIGN
318 #define IF_ASSIGN(var, entry, etype, id)		\
319 	if (FTRACE_CMP_TYPE(var, etype)) {		\
320 		var = (typeof(var))(entry);		\
321 		WARN_ON(id && (entry)->type != id);	\
322 		break;					\
323 	}
324 
325 /* Will cause compile errors if type is not found. */
326 extern void __ftrace_bad_type(void);
327 
328 /*
329  * The trace_assign_type is a verifier that the entry type is
330  * the same as the type being assigned. To add new types simply
331  * add a line with the following format:
332  *
333  * IF_ASSIGN(var, ent, type, id);
334  *
335  *  Where "type" is the trace type that includes the trace_entry
336  *  as the "ent" item. And "id" is the trace identifier that is
337  *  used in the trace_type enum.
338  *
339  *  If the type can have more than one id, then use zero.
340  */
341 #define trace_assign_type(var, ent)					\
342 	do {								\
343 		IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);	\
344 		IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);	\
345 		IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);	\
346 		IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
347 		IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);	\
348 		IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT);	\
349 		IF_ASSIGN(var, ent, struct bputs_entry, TRACE_BPUTS);	\
350 		IF_ASSIGN(var, ent, struct hwlat_entry, TRACE_HWLAT);	\
351 		IF_ASSIGN(var, ent, struct raw_data_entry, TRACE_RAW_DATA);\
352 		IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,		\
353 			  TRACE_MMIO_RW);				\
354 		IF_ASSIGN(var, ent, struct trace_mmiotrace_map,		\
355 			  TRACE_MMIO_MAP);				\
356 		IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
357 		IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,	\
358 			  TRACE_GRAPH_ENT);		\
359 		IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,	\
360 			  TRACE_GRAPH_RET);		\
361 		__ftrace_bad_type();					\
362 	} while (0)
363 
364 /*
365  * An option specific to a tracer. This is a boolean value.
366  * The bit is the bit index that sets its value on the
367  * flags value in struct tracer_flags.
368  */
369 struct tracer_opt {
370 	const char	*name; /* Will appear on the trace_options file */
371 	u32		bit; /* Mask assigned in val field in tracer_flags */
372 };
373 
374 /*
375  * The set of specific options for a tracer. Your tracer
376  * have to set the initial value of the flags val.
377  */
378 struct tracer_flags {
379 	u32			val;
380 	struct tracer_opt	*opts;
381 	struct tracer		*trace;
382 };
383 
384 /* Makes more easy to define a tracer opt */
385 #define TRACER_OPT(s, b)	.name = #s, .bit = b
386 
387 
388 struct trace_option_dentry {
389 	struct tracer_opt		*opt;
390 	struct tracer_flags		*flags;
391 	struct trace_array		*tr;
392 	struct dentry			*entry;
393 };
394 
395 /**
396  * struct tracer - a specific tracer and its callbacks to interact with tracefs
397  * @name: the name chosen to select it on the available_tracers file
398  * @init: called when one switches to this tracer (echo name > current_tracer)
399  * @reset: called when one switches to another tracer
400  * @start: called when tracing is unpaused (echo 1 > tracing_on)
401  * @stop: called when tracing is paused (echo 0 > tracing_on)
402  * @update_thresh: called when tracing_thresh is updated
403  * @open: called when the trace file is opened
404  * @pipe_open: called when the trace_pipe file is opened
405  * @close: called when the trace file is released
406  * @pipe_close: called when the trace_pipe file is released
407  * @read: override the default read callback on trace_pipe
408  * @splice_read: override the default splice_read callback on trace_pipe
409  * @selftest: selftest to run on boot (see trace_selftest.c)
410  * @print_headers: override the first lines that describe your columns
411  * @print_line: callback that prints a trace
412  * @set_flag: signals one of your private flags changed (trace_options file)
413  * @flags: your private flags
414  */
415 struct tracer {
416 	const char		*name;
417 	int			(*init)(struct trace_array *tr);
418 	void			(*reset)(struct trace_array *tr);
419 	void			(*start)(struct trace_array *tr);
420 	void			(*stop)(struct trace_array *tr);
421 	int			(*update_thresh)(struct trace_array *tr);
422 	void			(*open)(struct trace_iterator *iter);
423 	void			(*pipe_open)(struct trace_iterator *iter);
424 	void			(*close)(struct trace_iterator *iter);
425 	void			(*pipe_close)(struct trace_iterator *iter);
426 	ssize_t			(*read)(struct trace_iterator *iter,
427 					struct file *filp, char __user *ubuf,
428 					size_t cnt, loff_t *ppos);
429 	ssize_t			(*splice_read)(struct trace_iterator *iter,
430 					       struct file *filp,
431 					       loff_t *ppos,
432 					       struct pipe_inode_info *pipe,
433 					       size_t len,
434 					       unsigned int flags);
435 #ifdef CONFIG_FTRACE_STARTUP_TEST
436 	int			(*selftest)(struct tracer *trace,
437 					    struct trace_array *tr);
438 #endif
439 	void			(*print_header)(struct seq_file *m);
440 	enum print_line_t	(*print_line)(struct trace_iterator *iter);
441 	/* If you handled the flag setting, return 0 */
442 	int			(*set_flag)(struct trace_array *tr,
443 					    u32 old_flags, u32 bit, int set);
444 	/* Return 0 if OK with change, else return non-zero */
445 	int			(*flag_changed)(struct trace_array *tr,
446 						u32 mask, int set);
447 	struct tracer		*next;
448 	struct tracer_flags	*flags;
449 	int			enabled;
450 	int			ref;
451 	bool			print_max;
452 	bool			allow_instances;
453 #ifdef CONFIG_TRACER_MAX_TRACE
454 	bool			use_max_tr;
455 #endif
456 	/* True if tracer cannot be enabled in kernel param */
457 	bool			noboot;
458 };
459 
460 
461 /* Only current can touch trace_recursion */
462 
463 /*
464  * For function tracing recursion:
465  *  The order of these bits are important.
466  *
467  *  When function tracing occurs, the following steps are made:
468  *   If arch does not support a ftrace feature:
469  *    call internal function (uses INTERNAL bits) which calls...
470  *   If callback is registered to the "global" list, the list
471  *    function is called and recursion checks the GLOBAL bits.
472  *    then this function calls...
473  *   The function callback, which can use the FTRACE bits to
474  *    check for recursion.
475  *
476  * Now if the arch does not suppport a feature, and it calls
477  * the global list function which calls the ftrace callback
478  * all three of these steps will do a recursion protection.
479  * There's no reason to do one if the previous caller already
480  * did. The recursion that we are protecting against will
481  * go through the same steps again.
482  *
483  * To prevent the multiple recursion checks, if a recursion
484  * bit is set that is higher than the MAX bit of the current
485  * check, then we know that the check was made by the previous
486  * caller, and we can skip the current check.
487  */
488 enum {
489 	TRACE_BUFFER_BIT,
490 	TRACE_BUFFER_NMI_BIT,
491 	TRACE_BUFFER_IRQ_BIT,
492 	TRACE_BUFFER_SIRQ_BIT,
493 
494 	/* Start of function recursion bits */
495 	TRACE_FTRACE_BIT,
496 	TRACE_FTRACE_NMI_BIT,
497 	TRACE_FTRACE_IRQ_BIT,
498 	TRACE_FTRACE_SIRQ_BIT,
499 
500 	/* INTERNAL_BITs must be greater than FTRACE_BITs */
501 	TRACE_INTERNAL_BIT,
502 	TRACE_INTERNAL_NMI_BIT,
503 	TRACE_INTERNAL_IRQ_BIT,
504 	TRACE_INTERNAL_SIRQ_BIT,
505 
506 	TRACE_BRANCH_BIT,
507 /*
508  * Abuse of the trace_recursion.
509  * As we need a way to maintain state if we are tracing the function
510  * graph in irq because we want to trace a particular function that
511  * was called in irq context but we have irq tracing off. Since this
512  * can only be modified by current, we can reuse trace_recursion.
513  */
514 	TRACE_IRQ_BIT,
515 };
516 
517 #define trace_recursion_set(bit)	do { (current)->trace_recursion |= (1<<(bit)); } while (0)
518 #define trace_recursion_clear(bit)	do { (current)->trace_recursion &= ~(1<<(bit)); } while (0)
519 #define trace_recursion_test(bit)	((current)->trace_recursion & (1<<(bit)))
520 
521 #define TRACE_CONTEXT_BITS	4
522 
523 #define TRACE_FTRACE_START	TRACE_FTRACE_BIT
524 #define TRACE_FTRACE_MAX	((1 << (TRACE_FTRACE_START + TRACE_CONTEXT_BITS)) - 1)
525 
526 #define TRACE_LIST_START	TRACE_INTERNAL_BIT
527 #define TRACE_LIST_MAX		((1 << (TRACE_LIST_START + TRACE_CONTEXT_BITS)) - 1)
528 
529 #define TRACE_CONTEXT_MASK	TRACE_LIST_MAX
530 
531 static __always_inline int trace_get_context_bit(void)
532 {
533 	int bit;
534 
535 	if (in_interrupt()) {
536 		if (in_nmi())
537 			bit = 0;
538 
539 		else if (in_irq())
540 			bit = 1;
541 		else
542 			bit = 2;
543 	} else
544 		bit = 3;
545 
546 	return bit;
547 }
548 
549 static __always_inline int trace_test_and_set_recursion(int start, int max)
550 {
551 	unsigned int val = current->trace_recursion;
552 	int bit;
553 
554 	/* A previous recursion check was made */
555 	if ((val & TRACE_CONTEXT_MASK) > max)
556 		return 0;
557 
558 	bit = trace_get_context_bit() + start;
559 	if (unlikely(val & (1 << bit)))
560 		return -1;
561 
562 	val |= 1 << bit;
563 	current->trace_recursion = val;
564 	barrier();
565 
566 	return bit;
567 }
568 
569 static __always_inline void trace_clear_recursion(int bit)
570 {
571 	unsigned int val = current->trace_recursion;
572 
573 	if (!bit)
574 		return;
575 
576 	bit = 1 << bit;
577 	val &= ~bit;
578 
579 	barrier();
580 	current->trace_recursion = val;
581 }
582 
583 static inline struct ring_buffer_iter *
584 trace_buffer_iter(struct trace_iterator *iter, int cpu)
585 {
586 	return iter->buffer_iter ? iter->buffer_iter[cpu] : NULL;
587 }
588 
589 int tracer_init(struct tracer *t, struct trace_array *tr);
590 int tracing_is_enabled(void);
591 void tracing_reset(struct trace_buffer *buf, int cpu);
592 void tracing_reset_online_cpus(struct trace_buffer *buf);
593 void tracing_reset_current(int cpu);
594 void tracing_reset_all_online_cpus(void);
595 int tracing_open_generic(struct inode *inode, struct file *filp);
596 bool tracing_is_disabled(void);
597 int tracer_tracing_is_on(struct trace_array *tr);
598 void tracer_tracing_on(struct trace_array *tr);
599 void tracer_tracing_off(struct trace_array *tr);
600 struct dentry *trace_create_file(const char *name,
601 				 umode_t mode,
602 				 struct dentry *parent,
603 				 void *data,
604 				 const struct file_operations *fops);
605 
606 struct dentry *tracing_init_dentry(void);
607 
608 struct ring_buffer_event;
609 
610 struct ring_buffer_event *
611 trace_buffer_lock_reserve(struct ring_buffer *buffer,
612 			  int type,
613 			  unsigned long len,
614 			  unsigned long flags,
615 			  int pc);
616 
617 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
618 						struct trace_array_cpu *data);
619 
620 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
621 					  int *ent_cpu, u64 *ent_ts);
622 
623 void trace_buffer_unlock_commit_nostack(struct ring_buffer *buffer,
624 					struct ring_buffer_event *event);
625 
626 int trace_empty(struct trace_iterator *iter);
627 
628 void *trace_find_next_entry_inc(struct trace_iterator *iter);
629 
630 void trace_init_global_iter(struct trace_iterator *iter);
631 
632 void tracing_iter_reset(struct trace_iterator *iter, int cpu);
633 
634 void trace_function(struct trace_array *tr,
635 		    unsigned long ip,
636 		    unsigned long parent_ip,
637 		    unsigned long flags, int pc);
638 void trace_graph_function(struct trace_array *tr,
639 		    unsigned long ip,
640 		    unsigned long parent_ip,
641 		    unsigned long flags, int pc);
642 void trace_latency_header(struct seq_file *m);
643 void trace_default_header(struct seq_file *m);
644 void print_trace_header(struct seq_file *m, struct trace_iterator *iter);
645 int trace_empty(struct trace_iterator *iter);
646 
647 void trace_graph_return(struct ftrace_graph_ret *trace);
648 int trace_graph_entry(struct ftrace_graph_ent *trace);
649 void set_graph_array(struct trace_array *tr);
650 
651 void tracing_start_cmdline_record(void);
652 void tracing_stop_cmdline_record(void);
653 void tracing_start_tgid_record(void);
654 void tracing_stop_tgid_record(void);
655 
656 int register_tracer(struct tracer *type);
657 int is_tracing_stopped(void);
658 
659 loff_t tracing_lseek(struct file *file, loff_t offset, int whence);
660 
661 extern cpumask_var_t __read_mostly tracing_buffer_mask;
662 
663 #define for_each_tracing_cpu(cpu)	\
664 	for_each_cpu(cpu, tracing_buffer_mask)
665 
666 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
667 
668 extern unsigned long tracing_thresh;
669 
670 /* PID filtering */
671 
672 extern int pid_max;
673 
674 bool trace_find_filtered_pid(struct trace_pid_list *filtered_pids,
675 			     pid_t search_pid);
676 bool trace_ignore_this_task(struct trace_pid_list *filtered_pids,
677 			    struct task_struct *task);
678 void trace_filter_add_remove_task(struct trace_pid_list *pid_list,
679 				  struct task_struct *self,
680 				  struct task_struct *task);
681 void *trace_pid_next(struct trace_pid_list *pid_list, void *v, loff_t *pos);
682 void *trace_pid_start(struct trace_pid_list *pid_list, loff_t *pos);
683 int trace_pid_show(struct seq_file *m, void *v);
684 void trace_free_pid_list(struct trace_pid_list *pid_list);
685 int trace_pid_write(struct trace_pid_list *filtered_pids,
686 		    struct trace_pid_list **new_pid_list,
687 		    const char __user *ubuf, size_t cnt);
688 
689 #ifdef CONFIG_TRACER_MAX_TRACE
690 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
691 void update_max_tr_single(struct trace_array *tr,
692 			  struct task_struct *tsk, int cpu);
693 #endif /* CONFIG_TRACER_MAX_TRACE */
694 
695 #ifdef CONFIG_STACKTRACE
696 void ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags,
697 			    int pc);
698 
699 void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
700 		   int pc);
701 #else
702 static inline void ftrace_trace_userstack(struct ring_buffer *buffer,
703 					  unsigned long flags, int pc)
704 {
705 }
706 
707 static inline void __trace_stack(struct trace_array *tr, unsigned long flags,
708 				 int skip, int pc)
709 {
710 }
711 #endif /* CONFIG_STACKTRACE */
712 
713 extern u64 ftrace_now(int cpu);
714 
715 extern void trace_find_cmdline(int pid, char comm[]);
716 extern int trace_find_tgid(int pid);
717 extern void trace_event_follow_fork(struct trace_array *tr, bool enable);
718 
719 #ifdef CONFIG_DYNAMIC_FTRACE
720 extern unsigned long ftrace_update_tot_cnt;
721 void ftrace_init_trace_array(struct trace_array *tr);
722 #else
723 static inline void ftrace_init_trace_array(struct trace_array *tr) { }
724 #endif
725 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
726 extern int DYN_FTRACE_TEST_NAME(void);
727 #define DYN_FTRACE_TEST_NAME2 trace_selftest_dynamic_test_func2
728 extern int DYN_FTRACE_TEST_NAME2(void);
729 
730 extern bool ring_buffer_expanded;
731 extern bool tracing_selftest_disabled;
732 
733 #ifdef CONFIG_FTRACE_STARTUP_TEST
734 extern int trace_selftest_startup_function(struct tracer *trace,
735 					   struct trace_array *tr);
736 extern int trace_selftest_startup_function_graph(struct tracer *trace,
737 						 struct trace_array *tr);
738 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
739 					  struct trace_array *tr);
740 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
741 					     struct trace_array *tr);
742 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
743 						 struct trace_array *tr);
744 extern int trace_selftest_startup_wakeup(struct tracer *trace,
745 					 struct trace_array *tr);
746 extern int trace_selftest_startup_nop(struct tracer *trace,
747 					 struct trace_array *tr);
748 extern int trace_selftest_startup_branch(struct tracer *trace,
749 					 struct trace_array *tr);
750 /*
751  * Tracer data references selftest functions that only occur
752  * on boot up. These can be __init functions. Thus, when selftests
753  * are enabled, then the tracers need to reference __init functions.
754  */
755 #define __tracer_data		__refdata
756 #else
757 /* Tracers are seldom changed. Optimize when selftests are disabled. */
758 #define __tracer_data		__read_mostly
759 #endif /* CONFIG_FTRACE_STARTUP_TEST */
760 
761 extern void *head_page(struct trace_array_cpu *data);
762 extern unsigned long long ns2usecs(u64 nsec);
763 extern int
764 trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
765 extern int
766 trace_vprintk(unsigned long ip, const char *fmt, va_list args);
767 extern int
768 trace_array_vprintk(struct trace_array *tr,
769 		    unsigned long ip, const char *fmt, va_list args);
770 int trace_array_printk(struct trace_array *tr,
771 		       unsigned long ip, const char *fmt, ...);
772 int trace_array_printk_buf(struct ring_buffer *buffer,
773 			   unsigned long ip, const char *fmt, ...);
774 void trace_printk_seq(struct trace_seq *s);
775 enum print_line_t print_trace_line(struct trace_iterator *iter);
776 
777 extern char trace_find_mark(unsigned long long duration);
778 
779 struct ftrace_hash;
780 
781 struct ftrace_mod_load {
782 	struct list_head	list;
783 	char			*func;
784 	char			*module;
785 	int			 enable;
786 };
787 
788 enum {
789 	FTRACE_HASH_FL_MOD	= (1 << 0),
790 };
791 
792 struct ftrace_hash {
793 	unsigned long		size_bits;
794 	struct hlist_head	*buckets;
795 	unsigned long		count;
796 	unsigned long		flags;
797 	struct rcu_head		rcu;
798 };
799 
800 struct ftrace_func_entry *
801 ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip);
802 
803 static __always_inline bool ftrace_hash_empty(struct ftrace_hash *hash)
804 {
805 	return !hash || !(hash->count || (hash->flags & FTRACE_HASH_FL_MOD));
806 }
807 
808 /* Standard output formatting function used for function return traces */
809 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
810 
811 /* Flag options */
812 #define TRACE_GRAPH_PRINT_OVERRUN       0x1
813 #define TRACE_GRAPH_PRINT_CPU           0x2
814 #define TRACE_GRAPH_PRINT_OVERHEAD      0x4
815 #define TRACE_GRAPH_PRINT_PROC          0x8
816 #define TRACE_GRAPH_PRINT_DURATION      0x10
817 #define TRACE_GRAPH_PRINT_ABS_TIME      0x20
818 #define TRACE_GRAPH_PRINT_IRQS          0x40
819 #define TRACE_GRAPH_PRINT_TAIL          0x80
820 #define TRACE_GRAPH_SLEEP_TIME		0x100
821 #define TRACE_GRAPH_GRAPH_TIME		0x200
822 #define TRACE_GRAPH_PRINT_FILL_SHIFT	28
823 #define TRACE_GRAPH_PRINT_FILL_MASK	(0x3 << TRACE_GRAPH_PRINT_FILL_SHIFT)
824 
825 extern void ftrace_graph_sleep_time_control(bool enable);
826 extern void ftrace_graph_graph_time_control(bool enable);
827 
828 extern enum print_line_t
829 print_graph_function_flags(struct trace_iterator *iter, u32 flags);
830 extern void print_graph_headers_flags(struct seq_file *s, u32 flags);
831 extern void
832 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
833 extern void graph_trace_open(struct trace_iterator *iter);
834 extern void graph_trace_close(struct trace_iterator *iter);
835 extern int __trace_graph_entry(struct trace_array *tr,
836 			       struct ftrace_graph_ent *trace,
837 			       unsigned long flags, int pc);
838 extern void __trace_graph_return(struct trace_array *tr,
839 				 struct ftrace_graph_ret *trace,
840 				 unsigned long flags, int pc);
841 
842 #ifdef CONFIG_DYNAMIC_FTRACE
843 extern struct ftrace_hash *ftrace_graph_hash;
844 extern struct ftrace_hash *ftrace_graph_notrace_hash;
845 
846 static inline int ftrace_graph_addr(unsigned long addr)
847 {
848 	int ret = 0;
849 
850 	preempt_disable_notrace();
851 
852 	if (ftrace_hash_empty(ftrace_graph_hash)) {
853 		ret = 1;
854 		goto out;
855 	}
856 
857 	if (ftrace_lookup_ip(ftrace_graph_hash, addr)) {
858 		/*
859 		 * If no irqs are to be traced, but a set_graph_function
860 		 * is set, and called by an interrupt handler, we still
861 		 * want to trace it.
862 		 */
863 		if (in_irq())
864 			trace_recursion_set(TRACE_IRQ_BIT);
865 		else
866 			trace_recursion_clear(TRACE_IRQ_BIT);
867 		ret = 1;
868 	}
869 
870 out:
871 	preempt_enable_notrace();
872 	return ret;
873 }
874 
875 static inline int ftrace_graph_notrace_addr(unsigned long addr)
876 {
877 	int ret = 0;
878 
879 	preempt_disable_notrace();
880 
881 	if (ftrace_lookup_ip(ftrace_graph_notrace_hash, addr))
882 		ret = 1;
883 
884 	preempt_enable_notrace();
885 	return ret;
886 }
887 #else
888 static inline int ftrace_graph_addr(unsigned long addr)
889 {
890 	return 1;
891 }
892 
893 static inline int ftrace_graph_notrace_addr(unsigned long addr)
894 {
895 	return 0;
896 }
897 #endif /* CONFIG_DYNAMIC_FTRACE */
898 
899 extern unsigned int fgraph_max_depth;
900 
901 static inline bool ftrace_graph_ignore_func(struct ftrace_graph_ent *trace)
902 {
903 	/* trace it when it is-nested-in or is a function enabled. */
904 	return !(trace->depth || ftrace_graph_addr(trace->func)) ||
905 		(trace->depth < 0) ||
906 		(fgraph_max_depth && trace->depth >= fgraph_max_depth);
907 }
908 
909 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
910 static inline enum print_line_t
911 print_graph_function_flags(struct trace_iterator *iter, u32 flags)
912 {
913 	return TRACE_TYPE_UNHANDLED;
914 }
915 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
916 
917 extern struct list_head ftrace_pids;
918 
919 #ifdef CONFIG_FUNCTION_TRACER
920 struct ftrace_func_command {
921 	struct list_head	list;
922 	char			*name;
923 	int			(*func)(struct trace_array *tr,
924 					struct ftrace_hash *hash,
925 					char *func, char *cmd,
926 					char *params, int enable);
927 };
928 extern bool ftrace_filter_param __initdata;
929 static inline int ftrace_trace_task(struct trace_array *tr)
930 {
931 	return !this_cpu_read(tr->trace_buffer.data->ftrace_ignore_pid);
932 }
933 extern int ftrace_is_dead(void);
934 int ftrace_create_function_files(struct trace_array *tr,
935 				 struct dentry *parent);
936 void ftrace_destroy_function_files(struct trace_array *tr);
937 void ftrace_init_global_array_ops(struct trace_array *tr);
938 void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func);
939 void ftrace_reset_array_ops(struct trace_array *tr);
940 int using_ftrace_ops_list_func(void);
941 void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer);
942 void ftrace_init_tracefs_toplevel(struct trace_array *tr,
943 				  struct dentry *d_tracer);
944 void ftrace_clear_pids(struct trace_array *tr);
945 int init_function_trace(void);
946 void ftrace_pid_follow_fork(struct trace_array *tr, bool enable);
947 #else
948 static inline int ftrace_trace_task(struct trace_array *tr)
949 {
950 	return 1;
951 }
952 static inline int ftrace_is_dead(void) { return 0; }
953 static inline int
954 ftrace_create_function_files(struct trace_array *tr,
955 			     struct dentry *parent)
956 {
957 	return 0;
958 }
959 static inline void ftrace_destroy_function_files(struct trace_array *tr) { }
960 static inline __init void
961 ftrace_init_global_array_ops(struct trace_array *tr) { }
962 static inline void ftrace_reset_array_ops(struct trace_array *tr) { }
963 static inline void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d) { }
964 static inline void ftrace_init_tracefs_toplevel(struct trace_array *tr, struct dentry *d) { }
965 static inline void ftrace_clear_pids(struct trace_array *tr) { }
966 static inline int init_function_trace(void) { return 0; }
967 static inline void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) { }
968 /* ftace_func_t type is not defined, use macro instead of static inline */
969 #define ftrace_init_array_ops(tr, func) do { } while (0)
970 #endif /* CONFIG_FUNCTION_TRACER */
971 
972 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE)
973 
974 struct ftrace_probe_ops {
975 	void			(*func)(unsigned long ip,
976 					unsigned long parent_ip,
977 					struct trace_array *tr,
978 					struct ftrace_probe_ops *ops,
979 					void *data);
980 	int			(*init)(struct ftrace_probe_ops *ops,
981 					struct trace_array *tr,
982 					unsigned long ip, void *init_data,
983 					void **data);
984 	void			(*free)(struct ftrace_probe_ops *ops,
985 					struct trace_array *tr,
986 					unsigned long ip, void *data);
987 	int			(*print)(struct seq_file *m,
988 					 unsigned long ip,
989 					 struct ftrace_probe_ops *ops,
990 					 void *data);
991 };
992 
993 struct ftrace_func_mapper;
994 typedef int (*ftrace_mapper_func)(void *data);
995 
996 struct ftrace_func_mapper *allocate_ftrace_func_mapper(void);
997 void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
998 					   unsigned long ip);
999 int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
1000 			       unsigned long ip, void *data);
1001 void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
1002 				   unsigned long ip);
1003 void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
1004 			     ftrace_mapper_func free_func);
1005 
1006 extern int
1007 register_ftrace_function_probe(char *glob, struct trace_array *tr,
1008 			       struct ftrace_probe_ops *ops, void *data);
1009 extern int
1010 unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
1011 				      struct ftrace_probe_ops *ops);
1012 extern void clear_ftrace_function_probes(struct trace_array *tr);
1013 
1014 int register_ftrace_command(struct ftrace_func_command *cmd);
1015 int unregister_ftrace_command(struct ftrace_func_command *cmd);
1016 
1017 void ftrace_create_filter_files(struct ftrace_ops *ops,
1018 				struct dentry *parent);
1019 void ftrace_destroy_filter_files(struct ftrace_ops *ops);
1020 #else
1021 struct ftrace_func_command;
1022 
1023 static inline __init int register_ftrace_command(struct ftrace_func_command *cmd)
1024 {
1025 	return -EINVAL;
1026 }
1027 static inline __init int unregister_ftrace_command(char *cmd_name)
1028 {
1029 	return -EINVAL;
1030 }
1031 static inline void clear_ftrace_function_probes(struct trace_array *tr)
1032 {
1033 }
1034 
1035 /*
1036  * The ops parameter passed in is usually undefined.
1037  * This must be a macro.
1038  */
1039 #define ftrace_create_filter_files(ops, parent) do { } while (0)
1040 #define ftrace_destroy_filter_files(ops) do { } while (0)
1041 #endif /* CONFIG_FUNCTION_TRACER && CONFIG_DYNAMIC_FTRACE */
1042 
1043 bool ftrace_event_is_function(struct trace_event_call *call);
1044 
1045 /*
1046  * struct trace_parser - servers for reading the user input separated by spaces
1047  * @cont: set if the input is not complete - no final space char was found
1048  * @buffer: holds the parsed user input
1049  * @idx: user input length
1050  * @size: buffer size
1051  */
1052 struct trace_parser {
1053 	bool		cont;
1054 	char		*buffer;
1055 	unsigned	idx;
1056 	unsigned	size;
1057 };
1058 
1059 static inline bool trace_parser_loaded(struct trace_parser *parser)
1060 {
1061 	return (parser->idx != 0);
1062 }
1063 
1064 static inline bool trace_parser_cont(struct trace_parser *parser)
1065 {
1066 	return parser->cont;
1067 }
1068 
1069 static inline void trace_parser_clear(struct trace_parser *parser)
1070 {
1071 	parser->cont = false;
1072 	parser->idx = 0;
1073 }
1074 
1075 extern int trace_parser_get_init(struct trace_parser *parser, int size);
1076 extern void trace_parser_put(struct trace_parser *parser);
1077 extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
1078 	size_t cnt, loff_t *ppos);
1079 
1080 /*
1081  * Only create function graph options if function graph is configured.
1082  */
1083 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1084 # define FGRAPH_FLAGS						\
1085 		C(DISPLAY_GRAPH,	"display-graph"),
1086 #else
1087 # define FGRAPH_FLAGS
1088 #endif
1089 
1090 #ifdef CONFIG_BRANCH_TRACER
1091 # define BRANCH_FLAGS					\
1092 		C(BRANCH,		"branch"),
1093 #else
1094 # define BRANCH_FLAGS
1095 #endif
1096 
1097 #ifdef CONFIG_FUNCTION_TRACER
1098 # define FUNCTION_FLAGS						\
1099 		C(FUNCTION,		"function-trace"),	\
1100 		C(FUNC_FORK,		"function-fork"),
1101 # define FUNCTION_DEFAULT_FLAGS		TRACE_ITER_FUNCTION
1102 #else
1103 # define FUNCTION_FLAGS
1104 # define FUNCTION_DEFAULT_FLAGS		0UL
1105 # define TRACE_ITER_FUNC_FORK		0UL
1106 #endif
1107 
1108 #ifdef CONFIG_STACKTRACE
1109 # define STACK_FLAGS				\
1110 		C(STACKTRACE,		"stacktrace"),
1111 #else
1112 # define STACK_FLAGS
1113 #endif
1114 
1115 /*
1116  * trace_iterator_flags is an enumeration that defines bit
1117  * positions into trace_flags that controls the output.
1118  *
1119  * NOTE: These bits must match the trace_options array in
1120  *       trace.c (this macro guarantees it).
1121  */
1122 #define TRACE_FLAGS						\
1123 		C(PRINT_PARENT,		"print-parent"),	\
1124 		C(SYM_OFFSET,		"sym-offset"),		\
1125 		C(SYM_ADDR,		"sym-addr"),		\
1126 		C(VERBOSE,		"verbose"),		\
1127 		C(RAW,			"raw"),			\
1128 		C(HEX,			"hex"),			\
1129 		C(BIN,			"bin"),			\
1130 		C(BLOCK,		"block"),		\
1131 		C(PRINTK,		"trace_printk"),	\
1132 		C(ANNOTATE,		"annotate"),		\
1133 		C(USERSTACKTRACE,	"userstacktrace"),	\
1134 		C(SYM_USEROBJ,		"sym-userobj"),		\
1135 		C(PRINTK_MSGONLY,	"printk-msg-only"),	\
1136 		C(CONTEXT_INFO,		"context-info"),   /* Print pid/cpu/time */ \
1137 		C(LATENCY_FMT,		"latency-format"),	\
1138 		C(RECORD_CMD,		"record-cmd"),		\
1139 		C(RECORD_TGID,		"record-tgid"),		\
1140 		C(OVERWRITE,		"overwrite"),		\
1141 		C(STOP_ON_FREE,		"disable_on_free"),	\
1142 		C(IRQ_INFO,		"irq-info"),		\
1143 		C(MARKERS,		"markers"),		\
1144 		C(EVENT_FORK,		"event-fork"),		\
1145 		FUNCTION_FLAGS					\
1146 		FGRAPH_FLAGS					\
1147 		STACK_FLAGS					\
1148 		BRANCH_FLAGS
1149 
1150 /*
1151  * By defining C, we can make TRACE_FLAGS a list of bit names
1152  * that will define the bits for the flag masks.
1153  */
1154 #undef C
1155 #define C(a, b) TRACE_ITER_##a##_BIT
1156 
1157 enum trace_iterator_bits {
1158 	TRACE_FLAGS
1159 	/* Make sure we don't go more than we have bits for */
1160 	TRACE_ITER_LAST_BIT
1161 };
1162 
1163 /*
1164  * By redefining C, we can make TRACE_FLAGS a list of masks that
1165  * use the bits as defined above.
1166  */
1167 #undef C
1168 #define C(a, b) TRACE_ITER_##a = (1 << TRACE_ITER_##a##_BIT)
1169 
1170 enum trace_iterator_flags { TRACE_FLAGS };
1171 
1172 /*
1173  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
1174  * control the output of kernel symbols.
1175  */
1176 #define TRACE_ITER_SYM_MASK \
1177 	(TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
1178 
1179 extern struct tracer nop_trace;
1180 
1181 #ifdef CONFIG_BRANCH_TRACER
1182 extern int enable_branch_tracing(struct trace_array *tr);
1183 extern void disable_branch_tracing(void);
1184 static inline int trace_branch_enable(struct trace_array *tr)
1185 {
1186 	if (tr->trace_flags & TRACE_ITER_BRANCH)
1187 		return enable_branch_tracing(tr);
1188 	return 0;
1189 }
1190 static inline void trace_branch_disable(void)
1191 {
1192 	/* due to races, always disable */
1193 	disable_branch_tracing();
1194 }
1195 #else
1196 static inline int trace_branch_enable(struct trace_array *tr)
1197 {
1198 	return 0;
1199 }
1200 static inline void trace_branch_disable(void)
1201 {
1202 }
1203 #endif /* CONFIG_BRANCH_TRACER */
1204 
1205 /* set ring buffers to default size if not already done so */
1206 int tracing_update_buffers(void);
1207 
1208 struct ftrace_event_field {
1209 	struct list_head	link;
1210 	const char		*name;
1211 	const char		*type;
1212 	int			filter_type;
1213 	int			offset;
1214 	int			size;
1215 	int			is_signed;
1216 };
1217 
1218 struct prog_entry;
1219 
1220 struct event_filter {
1221 	struct prog_entry __rcu	*prog;
1222 	char			*filter_string;
1223 };
1224 
1225 struct event_subsystem {
1226 	struct list_head	list;
1227 	const char		*name;
1228 	struct event_filter	*filter;
1229 	int			ref_count;
1230 };
1231 
1232 struct trace_subsystem_dir {
1233 	struct list_head		list;
1234 	struct event_subsystem		*subsystem;
1235 	struct trace_array		*tr;
1236 	struct dentry			*entry;
1237 	int				ref_count;
1238 	int				nr_events;
1239 };
1240 
1241 extern int call_filter_check_discard(struct trace_event_call *call, void *rec,
1242 				     struct ring_buffer *buffer,
1243 				     struct ring_buffer_event *event);
1244 
1245 void trace_buffer_unlock_commit_regs(struct trace_array *tr,
1246 				     struct ring_buffer *buffer,
1247 				     struct ring_buffer_event *event,
1248 				     unsigned long flags, int pc,
1249 				     struct pt_regs *regs);
1250 
1251 static inline void trace_buffer_unlock_commit(struct trace_array *tr,
1252 					      struct ring_buffer *buffer,
1253 					      struct ring_buffer_event *event,
1254 					      unsigned long flags, int pc)
1255 {
1256 	trace_buffer_unlock_commit_regs(tr, buffer, event, flags, pc, NULL);
1257 }
1258 
1259 DECLARE_PER_CPU(struct ring_buffer_event *, trace_buffered_event);
1260 DECLARE_PER_CPU(int, trace_buffered_event_cnt);
1261 void trace_buffered_event_disable(void);
1262 void trace_buffered_event_enable(void);
1263 
1264 static inline void
1265 __trace_event_discard_commit(struct ring_buffer *buffer,
1266 			     struct ring_buffer_event *event)
1267 {
1268 	if (this_cpu_read(trace_buffered_event) == event) {
1269 		/* Simply release the temp buffer */
1270 		this_cpu_dec(trace_buffered_event_cnt);
1271 		return;
1272 	}
1273 	ring_buffer_discard_commit(buffer, event);
1274 }
1275 
1276 /*
1277  * Helper function for event_trigger_unlock_commit{_regs}().
1278  * If there are event triggers attached to this event that requires
1279  * filtering against its fields, then they wil be called as the
1280  * entry already holds the field information of the current event.
1281  *
1282  * It also checks if the event should be discarded or not.
1283  * It is to be discarded if the event is soft disabled and the
1284  * event was only recorded to process triggers, or if the event
1285  * filter is active and this event did not match the filters.
1286  *
1287  * Returns true if the event is discarded, false otherwise.
1288  */
1289 static inline bool
1290 __event_trigger_test_discard(struct trace_event_file *file,
1291 			     struct ring_buffer *buffer,
1292 			     struct ring_buffer_event *event,
1293 			     void *entry,
1294 			     enum event_trigger_type *tt)
1295 {
1296 	unsigned long eflags = file->flags;
1297 
1298 	if (eflags & EVENT_FILE_FL_TRIGGER_COND)
1299 		*tt = event_triggers_call(file, entry, event);
1300 
1301 	if (test_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags) ||
1302 	    (unlikely(file->flags & EVENT_FILE_FL_FILTERED) &&
1303 	     !filter_match_preds(file->filter, entry))) {
1304 		__trace_event_discard_commit(buffer, event);
1305 		return true;
1306 	}
1307 
1308 	return false;
1309 }
1310 
1311 /**
1312  * event_trigger_unlock_commit - handle triggers and finish event commit
1313  * @file: The file pointer assoctiated to the event
1314  * @buffer: The ring buffer that the event is being written to
1315  * @event: The event meta data in the ring buffer
1316  * @entry: The event itself
1317  * @irq_flags: The state of the interrupts at the start of the event
1318  * @pc: The state of the preempt count at the start of the event.
1319  *
1320  * This is a helper function to handle triggers that require data
1321  * from the event itself. It also tests the event against filters and
1322  * if the event is soft disabled and should be discarded.
1323  */
1324 static inline void
1325 event_trigger_unlock_commit(struct trace_event_file *file,
1326 			    struct ring_buffer *buffer,
1327 			    struct ring_buffer_event *event,
1328 			    void *entry, unsigned long irq_flags, int pc)
1329 {
1330 	enum event_trigger_type tt = ETT_NONE;
1331 
1332 	if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
1333 		trace_buffer_unlock_commit(file->tr, buffer, event, irq_flags, pc);
1334 
1335 	if (tt)
1336 		event_triggers_post_call(file, tt);
1337 }
1338 
1339 /**
1340  * event_trigger_unlock_commit_regs - handle triggers and finish event commit
1341  * @file: The file pointer assoctiated to the event
1342  * @buffer: The ring buffer that the event is being written to
1343  * @event: The event meta data in the ring buffer
1344  * @entry: The event itself
1345  * @irq_flags: The state of the interrupts at the start of the event
1346  * @pc: The state of the preempt count at the start of the event.
1347  *
1348  * This is a helper function to handle triggers that require data
1349  * from the event itself. It also tests the event against filters and
1350  * if the event is soft disabled and should be discarded.
1351  *
1352  * Same as event_trigger_unlock_commit() but calls
1353  * trace_buffer_unlock_commit_regs() instead of trace_buffer_unlock_commit().
1354  */
1355 static inline void
1356 event_trigger_unlock_commit_regs(struct trace_event_file *file,
1357 				 struct ring_buffer *buffer,
1358 				 struct ring_buffer_event *event,
1359 				 void *entry, unsigned long irq_flags, int pc,
1360 				 struct pt_regs *regs)
1361 {
1362 	enum event_trigger_type tt = ETT_NONE;
1363 
1364 	if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
1365 		trace_buffer_unlock_commit_regs(file->tr, buffer, event,
1366 						irq_flags, pc, regs);
1367 
1368 	if (tt)
1369 		event_triggers_post_call(file, tt);
1370 }
1371 
1372 #define FILTER_PRED_INVALID	((unsigned short)-1)
1373 #define FILTER_PRED_IS_RIGHT	(1 << 15)
1374 #define FILTER_PRED_FOLD	(1 << 15)
1375 
1376 /*
1377  * The max preds is the size of unsigned short with
1378  * two flags at the MSBs. One bit is used for both the IS_RIGHT
1379  * and FOLD flags. The other is reserved.
1380  *
1381  * 2^14 preds is way more than enough.
1382  */
1383 #define MAX_FILTER_PRED		16384
1384 
1385 struct filter_pred;
1386 struct regex;
1387 
1388 typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event);
1389 
1390 typedef int (*regex_match_func)(char *str, struct regex *r, int len);
1391 
1392 enum regex_type {
1393 	MATCH_FULL = 0,
1394 	MATCH_FRONT_ONLY,
1395 	MATCH_MIDDLE_ONLY,
1396 	MATCH_END_ONLY,
1397 	MATCH_GLOB,
1398 };
1399 
1400 struct regex {
1401 	char			pattern[MAX_FILTER_STR_VAL];
1402 	int			len;
1403 	int			field_len;
1404 	regex_match_func	match;
1405 };
1406 
1407 struct filter_pred {
1408 	filter_pred_fn_t 	fn;
1409 	u64 			val;
1410 	struct regex		regex;
1411 	unsigned short		*ops;
1412 	struct ftrace_event_field *field;
1413 	int 			offset;
1414 	int			not;
1415 	int 			op;
1416 };
1417 
1418 static inline bool is_string_field(struct ftrace_event_field *field)
1419 {
1420 	return field->filter_type == FILTER_DYN_STRING ||
1421 	       field->filter_type == FILTER_STATIC_STRING ||
1422 	       field->filter_type == FILTER_PTR_STRING ||
1423 	       field->filter_type == FILTER_COMM;
1424 }
1425 
1426 static inline bool is_function_field(struct ftrace_event_field *field)
1427 {
1428 	return field->filter_type == FILTER_TRACE_FN;
1429 }
1430 
1431 extern enum regex_type
1432 filter_parse_regex(char *buff, int len, char **search, int *not);
1433 extern void print_event_filter(struct trace_event_file *file,
1434 			       struct trace_seq *s);
1435 extern int apply_event_filter(struct trace_event_file *file,
1436 			      char *filter_string);
1437 extern int apply_subsystem_event_filter(struct trace_subsystem_dir *dir,
1438 					char *filter_string);
1439 extern void print_subsystem_event_filter(struct event_subsystem *system,
1440 					 struct trace_seq *s);
1441 extern int filter_assign_type(const char *type);
1442 extern int create_event_filter(struct trace_event_call *call,
1443 			       char *filter_str, bool set_str,
1444 			       struct event_filter **filterp);
1445 extern void free_event_filter(struct event_filter *filter);
1446 
1447 struct ftrace_event_field *
1448 trace_find_event_field(struct trace_event_call *call, char *name);
1449 
1450 extern void trace_event_enable_cmd_record(bool enable);
1451 extern void trace_event_enable_tgid_record(bool enable);
1452 
1453 extern int event_trace_init(void);
1454 extern int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr);
1455 extern int event_trace_del_tracer(struct trace_array *tr);
1456 
1457 extern struct trace_event_file *__find_event_file(struct trace_array *tr,
1458 						  const char *system,
1459 						  const char *event);
1460 extern struct trace_event_file *find_event_file(struct trace_array *tr,
1461 						const char *system,
1462 						const char *event);
1463 
1464 static inline void *event_file_data(struct file *filp)
1465 {
1466 	return READ_ONCE(file_inode(filp)->i_private);
1467 }
1468 
1469 extern struct mutex event_mutex;
1470 extern struct list_head ftrace_events;
1471 
1472 extern const struct file_operations event_trigger_fops;
1473 extern const struct file_operations event_hist_fops;
1474 
1475 #ifdef CONFIG_HIST_TRIGGERS
1476 extern int register_trigger_hist_cmd(void);
1477 extern int register_trigger_hist_enable_disable_cmds(void);
1478 #else
1479 static inline int register_trigger_hist_cmd(void) { return 0; }
1480 static inline int register_trigger_hist_enable_disable_cmds(void) { return 0; }
1481 #endif
1482 
1483 extern int register_trigger_cmds(void);
1484 extern void clear_event_triggers(struct trace_array *tr);
1485 
1486 struct event_trigger_data {
1487 	unsigned long			count;
1488 	int				ref;
1489 	struct event_trigger_ops	*ops;
1490 	struct event_command		*cmd_ops;
1491 	struct event_filter __rcu	*filter;
1492 	char				*filter_str;
1493 	void				*private_data;
1494 	bool				paused;
1495 	bool				paused_tmp;
1496 	struct list_head		list;
1497 	char				*name;
1498 	struct list_head		named_list;
1499 	struct event_trigger_data	*named_data;
1500 };
1501 
1502 /* Avoid typos */
1503 #define ENABLE_EVENT_STR	"enable_event"
1504 #define DISABLE_EVENT_STR	"disable_event"
1505 #define ENABLE_HIST_STR		"enable_hist"
1506 #define DISABLE_HIST_STR	"disable_hist"
1507 
1508 struct enable_trigger_data {
1509 	struct trace_event_file		*file;
1510 	bool				enable;
1511 	bool				hist;
1512 };
1513 
1514 extern int event_enable_trigger_print(struct seq_file *m,
1515 				      struct event_trigger_ops *ops,
1516 				      struct event_trigger_data *data);
1517 extern void event_enable_trigger_free(struct event_trigger_ops *ops,
1518 				      struct event_trigger_data *data);
1519 extern int event_enable_trigger_func(struct event_command *cmd_ops,
1520 				     struct trace_event_file *file,
1521 				     char *glob, char *cmd, char *param);
1522 extern int event_enable_register_trigger(char *glob,
1523 					 struct event_trigger_ops *ops,
1524 					 struct event_trigger_data *data,
1525 					 struct trace_event_file *file);
1526 extern void event_enable_unregister_trigger(char *glob,
1527 					    struct event_trigger_ops *ops,
1528 					    struct event_trigger_data *test,
1529 					    struct trace_event_file *file);
1530 extern void trigger_data_free(struct event_trigger_data *data);
1531 extern int event_trigger_init(struct event_trigger_ops *ops,
1532 			      struct event_trigger_data *data);
1533 extern int trace_event_trigger_enable_disable(struct trace_event_file *file,
1534 					      int trigger_enable);
1535 extern void update_cond_flag(struct trace_event_file *file);
1536 extern void unregister_trigger(char *glob, struct event_trigger_ops *ops,
1537 			       struct event_trigger_data *test,
1538 			       struct trace_event_file *file);
1539 extern int set_trigger_filter(char *filter_str,
1540 			      struct event_trigger_data *trigger_data,
1541 			      struct trace_event_file *file);
1542 extern struct event_trigger_data *find_named_trigger(const char *name);
1543 extern bool is_named_trigger(struct event_trigger_data *test);
1544 extern int save_named_trigger(const char *name,
1545 			      struct event_trigger_data *data);
1546 extern void del_named_trigger(struct event_trigger_data *data);
1547 extern void pause_named_trigger(struct event_trigger_data *data);
1548 extern void unpause_named_trigger(struct event_trigger_data *data);
1549 extern void set_named_trigger_data(struct event_trigger_data *data,
1550 				   struct event_trigger_data *named_data);
1551 extern struct event_trigger_data *
1552 get_named_trigger_data(struct event_trigger_data *data);
1553 extern int register_event_command(struct event_command *cmd);
1554 extern int unregister_event_command(struct event_command *cmd);
1555 extern int register_trigger_hist_enable_disable_cmds(void);
1556 
1557 /**
1558  * struct event_trigger_ops - callbacks for trace event triggers
1559  *
1560  * The methods in this structure provide per-event trigger hooks for
1561  * various trigger operations.
1562  *
1563  * All the methods below, except for @init() and @free(), must be
1564  * implemented.
1565  *
1566  * @func: The trigger 'probe' function called when the triggering
1567  *	event occurs.  The data passed into this callback is the data
1568  *	that was supplied to the event_command @reg() function that
1569  *	registered the trigger (see struct event_command) along with
1570  *	the trace record, rec.
1571  *
1572  * @init: An optional initialization function called for the trigger
1573  *	when the trigger is registered (via the event_command reg()
1574  *	function).  This can be used to perform per-trigger
1575  *	initialization such as incrementing a per-trigger reference
1576  *	count, for instance.  This is usually implemented by the
1577  *	generic utility function @event_trigger_init() (see
1578  *	trace_event_triggers.c).
1579  *
1580  * @free: An optional de-initialization function called for the
1581  *	trigger when the trigger is unregistered (via the
1582  *	event_command @reg() function).  This can be used to perform
1583  *	per-trigger de-initialization such as decrementing a
1584  *	per-trigger reference count and freeing corresponding trigger
1585  *	data, for instance.  This is usually implemented by the
1586  *	generic utility function @event_trigger_free() (see
1587  *	trace_event_triggers.c).
1588  *
1589  * @print: The callback function invoked to have the trigger print
1590  *	itself.  This is usually implemented by a wrapper function
1591  *	that calls the generic utility function @event_trigger_print()
1592  *	(see trace_event_triggers.c).
1593  */
1594 struct event_trigger_ops {
1595 	void			(*func)(struct event_trigger_data *data,
1596 					void *rec,
1597 					struct ring_buffer_event *rbe);
1598 	int			(*init)(struct event_trigger_ops *ops,
1599 					struct event_trigger_data *data);
1600 	void			(*free)(struct event_trigger_ops *ops,
1601 					struct event_trigger_data *data);
1602 	int			(*print)(struct seq_file *m,
1603 					 struct event_trigger_ops *ops,
1604 					 struct event_trigger_data *data);
1605 };
1606 
1607 /**
1608  * struct event_command - callbacks and data members for event commands
1609  *
1610  * Event commands are invoked by users by writing the command name
1611  * into the 'trigger' file associated with a trace event.  The
1612  * parameters associated with a specific invocation of an event
1613  * command are used to create an event trigger instance, which is
1614  * added to the list of trigger instances associated with that trace
1615  * event.  When the event is hit, the set of triggers associated with
1616  * that event is invoked.
1617  *
1618  * The data members in this structure provide per-event command data
1619  * for various event commands.
1620  *
1621  * All the data members below, except for @post_trigger, must be set
1622  * for each event command.
1623  *
1624  * @name: The unique name that identifies the event command.  This is
1625  *	the name used when setting triggers via trigger files.
1626  *
1627  * @trigger_type: A unique id that identifies the event command
1628  *	'type'.  This value has two purposes, the first to ensure that
1629  *	only one trigger of the same type can be set at a given time
1630  *	for a particular event e.g. it doesn't make sense to have both
1631  *	a traceon and traceoff trigger attached to a single event at
1632  *	the same time, so traceon and traceoff have the same type
1633  *	though they have different names.  The @trigger_type value is
1634  *	also used as a bit value for deferring the actual trigger
1635  *	action until after the current event is finished.  Some
1636  *	commands need to do this if they themselves log to the trace
1637  *	buffer (see the @post_trigger() member below).  @trigger_type
1638  *	values are defined by adding new values to the trigger_type
1639  *	enum in include/linux/trace_events.h.
1640  *
1641  * @flags: See the enum event_command_flags below.
1642  *
1643  * All the methods below, except for @set_filter() and @unreg_all(),
1644  * must be implemented.
1645  *
1646  * @func: The callback function responsible for parsing and
1647  *	registering the trigger written to the 'trigger' file by the
1648  *	user.  It allocates the trigger instance and registers it with
1649  *	the appropriate trace event.  It makes use of the other
1650  *	event_command callback functions to orchestrate this, and is
1651  *	usually implemented by the generic utility function
1652  *	@event_trigger_callback() (see trace_event_triggers.c).
1653  *
1654  * @reg: Adds the trigger to the list of triggers associated with the
1655  *	event, and enables the event trigger itself, after
1656  *	initializing it (via the event_trigger_ops @init() function).
1657  *	This is also where commands can use the @trigger_type value to
1658  *	make the decision as to whether or not multiple instances of
1659  *	the trigger should be allowed.  This is usually implemented by
1660  *	the generic utility function @register_trigger() (see
1661  *	trace_event_triggers.c).
1662  *
1663  * @unreg: Removes the trigger from the list of triggers associated
1664  *	with the event, and disables the event trigger itself, after
1665  *	initializing it (via the event_trigger_ops @free() function).
1666  *	This is usually implemented by the generic utility function
1667  *	@unregister_trigger() (see trace_event_triggers.c).
1668  *
1669  * @unreg_all: An optional function called to remove all the triggers
1670  *	from the list of triggers associated with the event.  Called
1671  *	when a trigger file is opened in truncate mode.
1672  *
1673  * @set_filter: An optional function called to parse and set a filter
1674  *	for the trigger.  If no @set_filter() method is set for the
1675  *	event command, filters set by the user for the command will be
1676  *	ignored.  This is usually implemented by the generic utility
1677  *	function @set_trigger_filter() (see trace_event_triggers.c).
1678  *
1679  * @get_trigger_ops: The callback function invoked to retrieve the
1680  *	event_trigger_ops implementation associated with the command.
1681  */
1682 struct event_command {
1683 	struct list_head	list;
1684 	char			*name;
1685 	enum event_trigger_type	trigger_type;
1686 	int			flags;
1687 	int			(*func)(struct event_command *cmd_ops,
1688 					struct trace_event_file *file,
1689 					char *glob, char *cmd, char *params);
1690 	int			(*reg)(char *glob,
1691 				       struct event_trigger_ops *ops,
1692 				       struct event_trigger_data *data,
1693 				       struct trace_event_file *file);
1694 	void			(*unreg)(char *glob,
1695 					 struct event_trigger_ops *ops,
1696 					 struct event_trigger_data *data,
1697 					 struct trace_event_file *file);
1698 	void			(*unreg_all)(struct trace_event_file *file);
1699 	int			(*set_filter)(char *filter_str,
1700 					      struct event_trigger_data *data,
1701 					      struct trace_event_file *file);
1702 	struct event_trigger_ops *(*get_trigger_ops)(char *cmd, char *param);
1703 };
1704 
1705 /**
1706  * enum event_command_flags - flags for struct event_command
1707  *
1708  * @POST_TRIGGER: A flag that says whether or not this command needs
1709  *	to have its action delayed until after the current event has
1710  *	been closed.  Some triggers need to avoid being invoked while
1711  *	an event is currently in the process of being logged, since
1712  *	the trigger may itself log data into the trace buffer.  Thus
1713  *	we make sure the current event is committed before invoking
1714  *	those triggers.  To do that, the trigger invocation is split
1715  *	in two - the first part checks the filter using the current
1716  *	trace record; if a command has the @post_trigger flag set, it
1717  *	sets a bit for itself in the return value, otherwise it
1718  *	directly invokes the trigger.  Once all commands have been
1719  *	either invoked or set their return flag, the current record is
1720  *	either committed or discarded.  At that point, if any commands
1721  *	have deferred their triggers, those commands are finally
1722  *	invoked following the close of the current event.  In other
1723  *	words, if the event_trigger_ops @func() probe implementation
1724  *	itself logs to the trace buffer, this flag should be set,
1725  *	otherwise it can be left unspecified.
1726  *
1727  * @NEEDS_REC: A flag that says whether or not this command needs
1728  *	access to the trace record in order to perform its function,
1729  *	regardless of whether or not it has a filter associated with
1730  *	it (filters make a trigger require access to the trace record
1731  *	but are not always present).
1732  */
1733 enum event_command_flags {
1734 	EVENT_CMD_FL_POST_TRIGGER	= 1,
1735 	EVENT_CMD_FL_NEEDS_REC		= 2,
1736 };
1737 
1738 static inline bool event_command_post_trigger(struct event_command *cmd_ops)
1739 {
1740 	return cmd_ops->flags & EVENT_CMD_FL_POST_TRIGGER;
1741 }
1742 
1743 static inline bool event_command_needs_rec(struct event_command *cmd_ops)
1744 {
1745 	return cmd_ops->flags & EVENT_CMD_FL_NEEDS_REC;
1746 }
1747 
1748 extern int trace_event_enable_disable(struct trace_event_file *file,
1749 				      int enable, int soft_disable);
1750 extern int tracing_alloc_snapshot(void);
1751 
1752 extern const char *__start___trace_bprintk_fmt[];
1753 extern const char *__stop___trace_bprintk_fmt[];
1754 
1755 extern const char *__start___tracepoint_str[];
1756 extern const char *__stop___tracepoint_str[];
1757 
1758 void trace_printk_control(bool enabled);
1759 void trace_printk_init_buffers(void);
1760 void trace_printk_start_comm(void);
1761 int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set);
1762 int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled);
1763 
1764 #define MAX_EVENT_NAME_LEN	64
1765 
1766 extern int trace_run_command(const char *buf, int (*createfn)(int, char**));
1767 extern ssize_t trace_parse_run_command(struct file *file,
1768 		const char __user *buffer, size_t count, loff_t *ppos,
1769 		int (*createfn)(int, char**));
1770 
1771 /*
1772  * Normal trace_printk() and friends allocates special buffers
1773  * to do the manipulation, as well as saves the print formats
1774  * into sections to display. But the trace infrastructure wants
1775  * to use these without the added overhead at the price of being
1776  * a bit slower (used mainly for warnings, where we don't care
1777  * about performance). The internal_trace_puts() is for such
1778  * a purpose.
1779  */
1780 #define internal_trace_puts(str) __trace_puts(_THIS_IP_, str, strlen(str))
1781 
1782 #undef FTRACE_ENTRY
1783 #define FTRACE_ENTRY(call, struct_name, id, tstruct, print, filter)	\
1784 	extern struct trace_event_call					\
1785 	__aligned(4) event_##call;
1786 #undef FTRACE_ENTRY_DUP
1787 #define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print, filter)	\
1788 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print), \
1789 		     filter)
1790 #undef FTRACE_ENTRY_PACKED
1791 #define FTRACE_ENTRY_PACKED(call, struct_name, id, tstruct, print, filter) \
1792 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print), \
1793 		     filter)
1794 
1795 #include "trace_entries.h"
1796 
1797 #if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_FUNCTION_TRACER)
1798 int perf_ftrace_event_register(struct trace_event_call *call,
1799 			       enum trace_reg type, void *data);
1800 #else
1801 #define perf_ftrace_event_register NULL
1802 #endif
1803 
1804 #ifdef CONFIG_FTRACE_SYSCALLS
1805 void init_ftrace_syscalls(void);
1806 const char *get_syscall_name(int syscall);
1807 #else
1808 static inline void init_ftrace_syscalls(void) { }
1809 static inline const char *get_syscall_name(int syscall)
1810 {
1811 	return NULL;
1812 }
1813 #endif
1814 
1815 #ifdef CONFIG_EVENT_TRACING
1816 void trace_event_init(void);
1817 void trace_event_eval_update(struct trace_eval_map **map, int len);
1818 #else
1819 static inline void __init trace_event_init(void) { }
1820 static inline void trace_event_eval_update(struct trace_eval_map **map, int len) { }
1821 #endif
1822 
1823 #ifdef CONFIG_TRACER_SNAPSHOT
1824 void tracing_snapshot_instance(struct trace_array *tr);
1825 int tracing_alloc_snapshot_instance(struct trace_array *tr);
1826 #else
1827 static inline void tracing_snapshot_instance(struct trace_array *tr) { }
1828 static inline int tracing_alloc_snapshot_instance(struct trace_array *tr)
1829 {
1830 	return 0;
1831 }
1832 #endif
1833 
1834 extern struct trace_iterator *tracepoint_print_iter;
1835 
1836 #endif /* _LINUX_KERNEL_TRACE_H */
1837